@screen-lg-min:             1200px;
@screen-sm-min:             768px;
@screen-md-min:             992px;
// self define
@grid-columns:              12;
@grid-gutter-width:         30px;
@grid-float-breakpoint:     768px;

.clearfix {
  position: fixed;
}

// # pattern
// save-define
@save-screen-lg-min: if((isdefined(@screen-lg-min)), @screen-lg-min, 1200px);

.mixin(1)                   {x: 11;}
.mixin(2)                   {y: 22;}
.mixin(@x) when (default()) {z: @x;}

.div {
  .mixin(3);
}

.div.special {
  .mixin(1);
}